Picker Unfocused event on UWP

Hi,

I have a problem with Xamarin Forms Picker.
I am using unfocused event to open a popup when user selects an item. On Android works well, when picker is closed event is fired but, in UWP, the event is fired when combobox popup is opened preventing change selection.

Anyone know how I can put an event when picker is closed for Android and UWP? I can't use SelectedIndexChanged because if the user choose the same item as the item is currently being selected then the selection is not changed and therefore this event will not be triggered.

Thanks in advance!